The term 'LAST ACT' can be defined by five different crossword solutions: END (3 letters), ENDING (6 letters), FINALE (6 letters), WINDUP (6 letters), and SWANSONG (8 letters). END is a noun meaning the concluding part of something, while ENDING is a noun meaning the last part or section of something. FINALE is a noun meaning the last part of a performance, WINDUP is a noun meaning the final preparation for something, and SWANSONG is a noun meaning a final performance or achievement.